These days, more and more offices and stores, including convenience stores, have come to employ an image forming apparatus, such as a digital multi-function peripheral. Such an image forming apparatus installed in a store, etc., usually serves with a charging device, such as a coin rack, connected to the apparatus. In carrying out print work using the image forming apparatus, an operator (person who carries out the print work) puts a larger amount of money than necessary into the charging apparatus in advance. When copying starts, the charge for a sheet of copy is deducted from the prepaid money, and the balance of the prepayment is returned to the operator when copying is completed.
In carrying out maintenance/management service for such an image forming apparatus, the image forming apparatus is connected to a network so that a management center (server), etc., keeps checking the use condition of the apparatus and service personnel carry out maintenance work, supply work, etc., on a regular or necessary basis. In this form of maintenance/management service, a charging method in which a charging is executed according to the number of papers put out (printed out) of the image forming apparatus is employed. For example, according to the method, an amount of charge is calculated based on the number of papers used in operation of the image forming apparatus to collect a service charge from a user (company, store, etc.).
A conventional charging system has been known, which system enables adjustment of an amount of charge on an image forming apparatus according to the volume of expendable supplies (e.g., see Japanese Laid-Open Patent Publication No. 2004-151703). The charging system has a plurality of printers and an information processing device, charging on each printer according to the number of papers printed out. The system charges a different amount of money for one printed out paper according to a contract providing different maintenance details.
When an image forming apparatus is installed in a store, as described above, and such a trouble as a paper jam is caused by the apparatus itself during a printing processing, the paper jam prevents the apparatus from putting out a printed matter for an operator (person who carries out print work), so that the store refunds the payment for the missed printed matter to the operator. The store, on the other hand, receives no refund from a management center (base station) in charge of maintenance/management for this matter.
As a result, the charge for the printed matter missed due to the jam is also included in a sum on a bill sent from the management center to the store, which sum is determined based on the charge for papers used, for such expendable supplies as toner, for use of the image forming apparatus, for maintenance work, etc. The user (company, store, etc.), therefore, faces a bill larger in sum than a bill payable for the number of printed matters actually produced by the image forming apparatus. This problem also arises in an application of the invention described in Japanese Laid-Open Patent Publication No. 2004-151703.